SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ca080d543bf4583940b0754762c188ba1d028aa7a17b9dc53028686b064ff35' 
  AND token = 'E08NUWfiW/MgaZFqTLu0UDFVfJqhuz+lXxBZnNQmv6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}